Official Title
Effect of the Interaction Between Environmental Factors and Genetic Predisposition on Long-term Blood Pressure in Chinese Population
Brief Title
Blood Pressure Follow-up Study in Two Chinese Cohorts(C-BPCS)
Protocol ID
NCT02734472
Lead Sponsor
First Affiliated Hospital Xi'an Jiaotong University
Brief Summary
Essential hypertension is a complex trait which results from interaction between
environmental factors and genetic factors. The aim of this study is to investigate the
effects of interaction between environmental factors and genetic factors on long-term
blood pressure (BP) based on two established cohorts including "the cohort of Hanzhong
adolescent hypertension study" and "the cohort of Mei county adult salt-sensitive
hypertension study". Firstly, the Hanzhong cohort-based follow-up study is designed to
observe the track of BP during the whole life time, and to explore the effects of many
risk factors (such as salt-sensitivity, obesity et al) on long-term BP and the occurrence
of hypertension, and also to analyze the relationship of different polymorphisms of
sodium and potassium metabolism-related gene with BP changes and target organ damages. In
addition, by using DNA samples collected from subjects of "Mei county adult
salt-sensitive hypertension study"in which all participants had completed a chronic salt
loading and potassium intervention trial, we attempt to examine the single nucleotide
polymorphisms (SNPs) of sodium and potassium metabolism-related genes, as well as the
relationship between these SNPs and BP responses to dietary sodium/potassium
intervention, long-term BP change, the risk of hypertension and target organ damages were
analyzed. This study would enable us to further explore the etiology of essential
hypertension as well as to identify new genetic markers for predicting early hypertension
and target organ damage.
Detailed Description
This study is a longitudinal cohort follow-up study. The main contents
include:(1)Questionnaire design: questionnaire is designed according to the research
contents and purposes. The standard questionnaires will be used to collect the general
information, dietary habits, lifestyle, medical history and family history
etc.(2)Anthropometric measurements: blood pressure, height, body weight,waist and hip,
pulse will be acquired by medical practitioners who received professional trainings based
on World Health Organization (WHO) standards, and passed relevant examinations.(3) Blood
and urine samples collection: morning fasting blood, nocturia, and 24-hour urine specimen
will be collected by medical staffs, and blind tubes will be set up according to 5% of
the total samples. Blood biochemistries including serum total cholesterol, HDL
cholesterol, LDL cholesterol, triglycerides, fasting glucose, creatinine and hsCRP can be
measured using automatic biochemical analyzer. The sodium and potassium concentrations in
the urine will be measured by flame photometry. The total sodium and potassium excretions
in urine in 24h were calculated by multiplying the concentration and 24-h volume of
urine. (4) Auxiliary examinations: Auxiliary examinations including carotid intima-media
thickness, endothelium-dependent vasodilation (FMD), measurements of brachial-ankle pulse
wave velocity (baPWV) and electrocardiographic parameters. The measurement will be done
in hospitals by medical practitioners who received professional trainings and passed
relevant examinations. (5) Single nucleotide polymorphisms detection: based on our
previous studies, sodium and potassium metabolism-related gene polymorphisms will be
detected using MassARRAY technology. (6) Data processing and statistics: we should input
the data to the database, and utilize softwares such as SPSS, STATA, Haploview and FBAT
to analyze. (7) Quality control: ① Questionnaire is strictly designed and amended by
epidemiologist and clinical experts. ② A standardized "Investigator Handbook" will be
stipulated according to the guidelines. ③ Staff members are required to do a rigorous
training and pass the exam. ④ The investigation process will be strictly supervised by
the principal investigator. ⑤ Data entry use the parallel double entry method. ⑥ During
laboratory testing, blank control and blind detection are applied to ensure the quality.
⑦ Data analysis is performed by 2-3 postgraduates, inconsistent data need to be double
checked.
Enrollment Count
5,298 participants
Eligibility Criteria
Inclusion Criteria:
1. Hanzhong cohort of Adolescent Hypertension Study:
- adolescents aged 6-15 years old in over 20 schools of three towns (Qili, Laojun
and Shayan) in Hanzhong, Shaanxi, China.
2. Mei county cohort of adult salt-sensitive hypertension study:
- Han individuals in rural northern China
- adults aged 18-60 years
- individuals who had a mean systolic BP (SBP) between 130-160 mmHg and/or a
diastolic BP (DBP) between 85-100 mmHg and no use of antihypertensive
medications were identified as the proband
- the probands'parents,siblings, spouses, and offspring were recruited for the
study.
Exclusion Criteria:
During the follow-up period, the exclusion criteria are as follows:
- Secondary hypertension
- a history of severe cardiovascular disease
- chronic kidney disease or liver disease
- unable to complete the examination
- unable/refuse to sign the informed consent form
Filters
Hypertension
UNKNOWN
CHILD
ADULT